From 2d6c4c84230df9ff99b626b52b11049e449632c9 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 20 Apr 2017 11:17:09 +0100 Subject: [PATCH] drm/i915: Use discardable buffers for rings The contents of a ring are only valid between HEAD and TAIL, when the ring is idle (HEAD == TAIL) we can simply let the pages go under memory pressure if they are not pinned by an active context. Any new content will be written after HEAD and so the ring will again be valid between HEAD and TAIL, everything outside can be discarded. Note that we take care of ensuring that we do not reset the HEAD backwards following a GPU hang on an idle ring. The same precautions are what enable us to use stolen memory for rings. Signed-off-by: Chris Wilson Link: http://patchwork.freedesktop.org/patch/msgid/20170420101709.27250-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen --- drivers/gpu/drm/i915/intel_ringbuffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 833740bf49c9..32afac6c754f 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1341,7 +1341,7 @@ intel_ring_create_vma(struct drm_i915_private *dev_priv, int size) obj = i915_gem_object_create_stolen(dev_priv, size); if (!obj) - obj = i915_gem_object_create(dev_priv, size); + obj = i915_gem_object_create_internal(dev_priv, size); if (IS_ERR(obj)) return ERR_CAST(obj); -- 2.20.1